Anthocyanin composition in Cabernet Sauvignon red wine vinegar obtained by submerged acetification

Vinegars elaborated from white wine can be characterized by their phenolic composition. Indeed, for authenticity purpose, phenolic composition can be used to identify Sherry and Balsamic vinegars. However, the phenolic composition of red wine vinegars has scarcely been studied. Anthocyanin compounds in particular remain largely unknown. This study focuses on the analysis of anthocyanin compounds in red wine vinegar and the effect of acetification with submerged culture on such vinegars.The vinegar used in this study was produced from a young Cabernet Sauvignon wine in a laboratory-scale fermenter. Subsequent analyses of both wine and vinegar included their anthocyanin profile (by LC/MS), and their non-anthocyanin phenolic profile (by LC/DAD). In addition, wine and vinegar anthocyanin extracts were fractionated by CCC to determine the contribution of the fractions to overall antioxidant activity (AA), using ORAC, FRAP and DPPH assays.A total of 20 anthocyanin compounds were identified in the vinegar. As far as we know, this is the first time that anthocyanin-derived pigments (pyranoanthocyanins and ethyl-linked compounds) have been identified in red vinegar in such detail. Moreover, an original contribution of this study is the identification for the first time of catechyl-pyranocyanidin-3-glucoside in vinegar and wine, as well as two anthocyanin compounds not previously reported in vinegar or Cabernet Sauvignon wine: acetyl vitisin B and coumaroyl vitisin B. After the acetification process, vitisin-type and ethyl-linked compounds increased and monomeric anthocyanins, phenolic acids (ferulic acid, caffeic acid and caftaric acid) and flavan-3-ol ((+)-catechin) decreased.Although the proportion by weight of the polymeric compound fraction is similar in wine and vinegar, the AA of these polymers in vinegar is significantly greater (p < 0.05). We have also determined for the first time an approximate value of AA for malvidin-3-(6-acetyl)-glucoside isolated from vinegar.